Screw-cutting lathe



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.0. W. RILEY. Screw Cutting Lathe'.

No. 233,702. Patented oct. 26,1880.

MPETERS. PHOTO-LITHQGRAPHER. WASAHINGTON. D C.

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No. 233,702. Patented oct. 26,1880.

N. PETERS4 PHOTLIYHOGRAPHER, WASHINGTOM D C- FFICEQ ATnNr CHARLES IV.RILEY, OF KNOXVILLE, TENNESSEE.

SCREW-CUTTI NG LATHE.

SPECIFICATION forming part of Letters Patent No. 233,702, dated October26,'1880.

To all whom it may concern Be it known that I, CHARLES WILLIAM RILEY, ofKnoxville, in the county of Knox and State of Tennessee, have inventedcertain new and useful Improvements in Screw-Guttin g Lathes, of whichthe following is a specification. v

My invention relates to certain improvements in the gearing used tocommunicate inotion from the live-spindle of a screw-cutting lathe tothe feeding-screw that operates the slide-rest.

On lathes as commonly used at present the change in the gearing forobtaining the desired pitch of any thread to be cut is effected byremoving one or more of the gear-wheels and inserting others in theirplaces, such change involving labor and loss of time.

In a planing-machine it has been proposed to use two intermeshing seriesof gear-wheels, the wheels of one series running loosely on theirspindle, and capable of being individually connected thereto at will;but such device is not practically adapted to a screw-cutting lathe,because it will not afford the required number of changes withoutincreasing the length of the lathe to toor great an extent.

In order to obviate these difficulties and yet keep the mechanism withinthe narrow limits to which the drive-gear of alathe must be conned, Iemploy two systems of wheels, one system being driven from thelive-spindle, and, in its turn, driving the other system thatcommunicates directly with the feedingscrew. Each system consists of twoseries of wheels, each series having a common spindle or shaft, and thewheels of one series being iixed to their spindle and intermeshing withthe wheels of the other series, which are made to turn loose upon theirspindle, except when some one of them is thrown into rigid connectiontherewith by mechanism hereinafter described.

rIhis mechanism for engaging and disen gaging at will any one of theloose wheels with their supportingshaft forms the second part of myinvention; and it consists of a radiallysliding key or dog in thespindle or shaft 0perated by a pin sliding in an inclined slot in thesame, and pushed in or out by a combined action of a central rod and anannular slide arranged concentrieally within the spindle,

Application led December 8, 1879.

l (which is made hollow to receive thcm,) and extending beyond the endof the same.

In order that my invention may be fully nnderstood, I will proceed todescribe the same with reference to the accompanying drawings, in which-Figure l represents a front elevation of the head-gearing and part ofthe bed and part of the feeding-screw of a screw-cutting lathe, the saidscrew being intended to feed the tool-carriage (not shown) in customarymanner. Fig. 2 is an end elevation of the said head-gear. Fig. 3 is alongitudinal section ot one of the compound spindles, hereinafterdescribed. Fig. 4 is a longitudinal section in the plane indicated bythe line 4 4, Fig. 2. Fig. 5 represents an index-table. Fig. 6 is a rearelevation ofthe head-gearing.

In the drawings, A is thespindlc, with which the work to be turned isconnected and revolves. B is a part of the screw, which may have a pitchof four, more or less, to the inch, and serves to propel the slidingcarriage (not shown) that holds the turning-tool. 0n the back end of thescrew are tixed rigidly thereto six gear-wheels, 42 48 50 56 63 66, eachcontaining a number of teeth corresponding to the figures thereon.

D is are volvin g spindle, on which are seven gear-wheels, six of which,56l 48 40 32 28 r24', are free to move thereon independently of themotion of the spindle and of each other, and have teeth corresponding innumber to the iigures on each, and working, respectively, into thewheels xed on the screw B. The seventh wheel, d, is fixed rigidly to thespindle D.

E is a stud, on which are tive gear-wheels, fixed and revolvingtogether, four of which, 34" 51 68 78, gear, respectively, into wheelson the spindle C, the fifth, e, gearing into and of the same number ci'teeth as the seventh wheel, d, on the spindle D.

The spindle C is constructed in the same manner as D, and has fourwheels, 24X 34X 5lx 68X, with teeth corresponding in number to thefigures on them, revolving in the same manner as those on I). On the endof the spindle U is a wheel, c, keyed to the spindle and gearing with awheel of half its number of teeth, keyed to the main spindle A.

. F represents a plate or standard, which sup- IOO ports and forms oneof the bearings of the spindles C and D. In Fig. 3, which may representa longitudinal section through the center of either' ofthe spindles G orD, y is ahollow spindle having a slot cut through it the width ot' thethickness of the adjustable key or dog fr, and the length of the spacethat the wheels will occupy on the spindle. The spindle y is supportedat its outer end in a bearing, z, iixed on the standard F, Figs. l and2, and extending outward therefrom in the form of a hollow stud, asrepresented in Fig. 3. Fitted coneentrieally in the hollow spindle y arean annular slide, yv, and a rod, o, capable of both common and relativemovement lougitudinally within said spindle, the slide U being guided bythe hollow stud e, and the rod 0 by the slide t. The slide 'U and rod 0,as well as the spindle y, are slotted to receive thc dog a', the slot inthe slide 'v being made to iit the dog, so as to et't'eet itslongitudinal adjustment, while that in the rod 0 is longer than thewidth of the dog, so as to permit the relative endwise movement of thesaid rod, which moves the dog radially out and in by the agency ot' pinq, lixed in the rod 0, and passing through an oblique slot in the dog Toretract the dog x within the spindle y the tingers are applied to thehead of the slide o, and the rod 0 pressed in with the thumb. The. slidec, carrying the dog, may then be moved endwise, as required, and onbeing' released the rod 0 is pushed out endwise by a spring, p, so astoadvance the dog and cause it to en- 3 gage with any one of the wheelsto which it may be set. rIhe adjustable key or dog w slides in andthroughout thelength ot' the slot in the hollow spindle y, passesthrough a slot in the rod 0, and is free to move up and down in a slotwhich it tits in the slide t, so as to engage with any one of the wheelson the spindle.

In Figs. l and 2, Gr and II are slides, having square holes, and free toslide on the square pieces L and M, which are screwed into the frame F.s and t are pins passing through the upper part of the slides G and Hand into the square studs L and M, respectively. The said square studshave holes corresponding in number with the letters thereon to receivethe pins s and t. 0n the lower parts of the slides G and Il are groovesto receive the collars Z- and t ofthe slides t.

Ve will now suppose that the spindles C and D are in thepositions shownin the drawings, the pins s and t in the holes A and F', respectively,and the keys fr (shown in Fig. 3) in the wheels 24K on spindle C, and 24on spindle D, which positions will give the common feed for turnin New,suppose it is desired to cut a thread with a pitch of eight to the inch.The necessary adjustment is effected as follows: Lift the pin s out ofthe hole in L and press the two knobs on the end of the spindletogether. This will draw the key down and out of the wheel 24K, leavingthe parts e and 0 of the spindle, together with the key, free to movehorizontally. Then by pulling these parts out the slide G will move withthem. Pull the knobs until the pin-hole in Gcomes fair with the hole Gin L and drop the pin in, which will leave the key in wheel 5l". Repeatthe same with spindle D until the pin drops in hole I, which will leavethe key in wheel 48 and give the desired pitch. Other pitches areobtained by setting the pins in the holes, as shown in the index-table,Fig. 5.

I am aware that it is not new to construct a feeding mechanism of twoseries of intermeshing gear-wheels, the wheels of one series xed totheir shaft, and the wheelsof the other series revolving loosely upon,but capable of being individually keyed to, their shaft; but such adevice is not well adapted to turninglathes on account of the roomrequired to accommodate it when sufficient wheels are added to cut theusual number of threads. Furthermore, in devices of this class asheretofore constructed it has always been necessary to either stop themachine when a change was to be made, or else to pass the locking-keyslowly from one wheel to the other instead of directly to the desiredwheel, whereas in my device, after having retracted the key, it may beslid back and forth to any desired position without stoppage or anyunnecessary waste of time.

Having thus described my invention, the following is what I claim as newtherein and desire to secure by Letters Patent:

l. In combination with two intermeshiug sets or series of cog-wheels,the wheels of one series of which are mounted loosely on a commonspindle, so that any one of said wheels may be placed in activeconnection therewith at will, a second double set or series ofintermeshing cog-wheels having the wheels of one series loose andadapted to be severally connected with their spindle and employed forvarying the speed of the lirst double series of cog-wheels, and inconnection with the first series of wheels loose and .adapted to beseverally connected with their spindle employed for varying the speedot' the feed-screw, as set forth.

2. In a screw-cutting lathe having a series of loose wheels withdiiferent numbers of teeth mounted on a common spindle, the combinationof the radially-sliding key or dog x, operating-rod o, annular slides c,and slidingindeXes Gr and H, substantially as and for the purposes setforth.

3. The combination of the spindle y, the annular slide o, rod o, pin q,and radially-sliding key or dog x, provided with an oblique slot toreceive the said pin q, as and for the purposes set forth.

CHAS. WM. RILEY.

Witnesses CHAs. H. BROWN, W. C. PERRY.

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